TERT transcriptional deregulation in thyroid cancer progression

项目总结/摘要 甲状腺癌进展过程中的TERT转录失调 我在研究生阶段接受了甲状腺癌遗传学方面的培训，在此期间，我鉴定了生殖系启动子， 赋予甲状腺癌易感性的变异。在我做博士后的时候，我领导了一个项目， 甲状腺低分化（PDTC）和间变性（ATC）的体细胞基因组学和转录组学标志 癌的我们报道了端粒酶逆转录酶（telomerase reverse transcriptase，TERT）基因启动子区的突变是导致肺癌的主要原因。 在通常致命的PDTC和ATC中最普遍的遗传改变，并构成疾病的良好生物标志物 严重性。尽管广泛接受TERT启动子突变激活基因转录，但特异性的启动子突变激活了基因转录。 这些改变的机制和生物学效应在很大程度上仍然未知。这促使我研究 甲状腺癌进展中TERT转录失调的作用，这是我的K22提案的主题。 我相信这个项目有很大的潜力，并将促进我建立自己的实验室。为此，我已 一个咨询委员会和合作者将在以下领域分享他们的专业知识和资源： 转录调控、染色质生物学和癌症的基因工程小鼠模型，以及 职业建议，而我则寻求获得终身教职这项建议概述了一项全面的办法 以表征端粒酶启动子突变在端粒酶转录失调和甲状腺癌中的作用。 癌症进展本项目的第一个目的是确定差异结合的转录复合物 TERT突变体与野生型启动子，为此，我提出了一个双重调控模型。首先，我们描述 实验来确定特定ETS家族成员在TERT突变启动子再激活中的作用，我们 相信与其他疾病背景下报告的不同。我们还将评估MAPK的作用 在ETS介导的TERT表达中的组成性信号传导，甲状腺肿瘤的标志。第二，我们的目标是揭开 CTCF基因组绝缘子通过远程增强子对TERT转录抑制的影响- 启动子相互作用我们有初步的数据表明ETS和CTCF因子竞争TERT 分别在突变体和野生型条件下的启动子结合，诱导对基因转录的相反作用。 我们的第二个目标是表征我们已经产生的第一个Tert突变启动子小鼠模型 通过等同小鼠基因座的CRISPR敲入。我们的初步数据表明，Tert促进甲状腺功能， 与甲状腺特异性致癌基因BrafV 600 E等位基因组合的癌症进展。我们还将评估哪些 信号通路参与Tert诱导的甲状腺肿瘤，以及它们是否产生独特的脆弱性 可以用于治疗总的来说，我的目标是建立自己作为一个独立的调查员， 甲状腺癌生物学和转录调控领域，以及K22赠款的授予将大大 促进这一过渡。

PROJECT SUMMARY / ABSTRACT TERT transcriptional deregulation in thyroid cancer progression I trained in thyroid cancer genetics in my graduate studies, during which time I identified germline promoter variants conferring thyroid cancer susceptibility. In my postdoctoral years I led a project that revealed the key somatic genomic and transcriptomic hallmarks of poorly differentiated (PDTC) and anaplastic (ATC) thyroid cancers. We reported that mutations in the promoter of TERT (telomerase reverse transcriptase) gene are the most prevalent genetic alterations in often fatal PDTCs and ATCs, and constitute good biomarkers of disease severity. Although it is widely accepted that TERT promoter mutations activate gene transcription, the specific mechanisms and biological effects of these alterations remain largely unknown. This prompted me to study the role of TERT transcriptional deregulation in thyroid cancer progression, which is the subject of my K22 proposal. I believe this project has great potential and will facilitate my setting up my own lab. To this end, I have put together an advisory committee and collaborators who will share their expertise and resources in the fields of transcriptional regulation, chromatin biology and genetically engineered mouse models of cancer, as well as career advice, while I seek to secure a tenure-track position. This proposal outlines a comprehensive approach to characterizing the role of TERT promoter mutations in telomerase transcriptional deregulation and thyroid cancer progression. The first aim of this project is to identify the transcriptional complex that differentially binds TERT mutant vs. wildtype promoter, and to this end I propose a dual regulation model. First, we describe experiments to define the role of specific ETS family members in TERT mutant promoter reactivation, which we believe are distinct from those reported in other disease contexts. We will also evaluate the effect of MAPK constitutive signaling, a hallmark of thyroid tumors, in ETS-mediated TERT expression. Second, we aim to unveil the influence of the CTCF genome insulator on TERT transcriptional repression through long-range enhancer- promoter interactions. We have preliminary data suggesting that ETS and CTCF factors compete for TERT promoter binding in mutant and wildtype conditions, respectively, inducing opposite effects on gene transcription. Our second aim is to characterize the first Tert mutant promoter mouse model, which we have already generated via CRISPR knock-in of the equivalent mouse locus. Our preliminary data suggest that Tert promotes thyroid cancer progression in combination with a thyroid-specific oncogenic BrafV600E allele. We will also assess which signaling pathways are involved in Tert-induced thyroid tumors, and whether they create unique vulnerabilities that can be exploited therapeutically. Overall, my goal is to establish myself as an independent investigator in the field of thyroid cancer biology and transcriptional regulation, and the awarding of the K22 grant will greatly facilitate this transition.